You Can't Leave
by CBloom2
Summary: Loosely based on spoilers for the next episode. I've included Jay in this because I was gutted that he's not going to be in this one. Not much Natalie because I wanted to concentrate on the brothers.
1. Chapter 1

So I'm writing this after seeing spoilers for the next Chicago **Med episode - so if you haven't seen the spoilers then don't read this. Obviously I don't know exactly what is going to happen but I'm really disappointed that Jay does not seem to be in it, even when the character's brother's life is on the line. So of course, I had to rectify that. So this is loosly based on what I've seen but including some brotherly love and fluff for Christmas.**

 **I have no medical knowledge whatsoever, so everything is totally made up to fit the story.**

 **Hope it 's ok. Obviously I don't own anyone that you recognise - they belong to the Chicago Med/PD/Fire universe.**

 **You Can't Leave**

"You ok?" Detective Jay Halstead asked his older brother, who was currently nursing a beer, seemingly deep in thought.

"Huh?" Was all the red haired doctor could muster as he glanced up at the younger man. Jay could see the dark shadows under Will's eyes - they seemed darker than the last time he had seen him.

"I said are you ok?" he repeated, "You've been staring into the bottom of that glass for the last twenty minutes..."

"Oh, sorry...yes I'm fine," Will answered, without conviction, placing the glass on the table.

"You know, if you didn't want to come here tonight, you only had to say. We could've made it another night," Jay told him.

"No, it's fine. I wanted to spend some time with you - we don't see each other enough," Will argued looking at his brother. He pulled himself up straighter and took a deep breath, "To be honest Jay, I've not had the best of days. I'm exhausted as it is, which is normal I know, but today this young girl just collapsed in the department and within a few hours nearly all her body was paralysed - we ended up having to intubate her. They made me go home as I had already done nearly two full shifts but I can't help wondering..."

Jay reached over and patted his arm. He knew that his brother took his patients seriously, no matter what - so not knowing what had caused the young girls paralysis would lay a heavy burden on the doctor, "I'm sorry Will. I wish there was something I could do," he told him sincerely.

Will smiled a tired smile, "You're doing it. We're spending time together - it's good."

They settled into a companionable silence as they both drank their beer, both deciding at the same time that it was time to call it a night.

"I'm just going to the mens room," Will told his brother, who followed his every move, a frown etched on his forehead.

"Hey Jay, rough day?" Matt Casey from Firehouse 51 broke into his musings.

Jay looked to the fireman, who was taking a beer from Kelly Severide as he spoke, "Hey guys. No more than usual."

"So why the long face?" Kelly asked.

"My doctor brother Will, he's had a tough day and I'm just a bit concerned about him," Jay told them.

Kelly smiled, "I know that feeling," he said as he rolled his eyes towards Casey.

Suddenly, Christopher Herrman, who ran the bar, shouted Jay's name. Jay, Matt and Kelly all ran to him, skidding to a halt when they arrived at his position. He was holding onto Will tightly, as if the red haired man would fall over if he let go, "Herrman, what's going on?" Matt asked in confusion.

"I was walking in as Will here decided he was going to fall out of the men's room..."

Jay looked from Herrman to his brother, who slowly raised his head - fear etched across his features, "Jay, I can't feel my foot..."

Jay stood, stunned for a few seconds, "What do you mean?"

"I mean, I can't feel my left foot, which is why I almost nose dived into Herrman here - my right foot has pins and needles in it..."

The Halstead brother's eyes met - horror in one set and fear in the other, "You don't think..." Jay stuttered.

Will shrugged, "I don't know - but it's possible that she was contageous."

"RIght, we're going to Med - come on I'll get you to the car," Jay threw one of Will's arms around his shoulders while Herrman didn't let go of the other side. They all but dragged him into Jay's car and he sped off towards the hospital.

On arrival, Jay launched himself through the doors, almost knocking April down in the process, "Sorry April," he said.#

She smiled at his apology, "It's ok. But what's the rush?"

"I need a wheelchair...it's Will..."

Two minutes later, Will was being wheeled (all be it grudingly) into the familiar department. Maggie was the first to see them after April, " Will what's wrong?" she asked, shocked to see the popular doctor being wheeled in.

"Maggie, what happened to that patient that I saw earlier, the one with the paralysis?" Will enquired.

"She's been intubated - but she's holding her own. Why do you ask?"

"He can't feel his foot," Jay explained watching Maggie's reaction carefully.

"I can't feel my FEET," Will emphasised.

Jay swallowed hard. Maggie could see that Jay was struggling so took control.

"Ok get him into trauma two...Dr Choi, just the man - there is your patient - off you go."

Ethan's eyes widened as he took in the scene before him, then the doctor in him took over once more and so it began...

Within half a hour, Will had been seen by just about every doctor imaginable, but unfortunately, none of them could tell him why this was happening to him. Jay could see that his brother was becoming increasingly frustrated and tried his best to calm him down.

Natalie had been in to see him, but Will had sent her away, afraid for her if it turned out to be contageous. He had tried to send Jay away too, but his stubborn brother had refused, saying that if it was contageous then he would already be infected.

Presently, Ethan came back into the room and closed the door behind him. Jay was immediately on alert when he saw the young doctor's expression, "How are we doing Will?" he asked, trying to keep his tone light.

Will noticed immediately, "What's wrong Ethan?" he demanded.

Ethan looked to both Halstead brothers as he dragged in a deep breath, "I'm sorry Will, but the girl died about ten minutes ago..."

Both brothers glanced at each other. Jay couldn't contain his shock and fear, whereas Will looked resigned, as he let his head drop back onto the pillow.

"So have we got any results from Will's tests?" Jay asked, trying to stay on task while his body was reeling from the shock.

"We've nothing conclusive..." was all the younger doctor could offer.

Jay couldn't take that, "You telling me that in this day and age, with all the technology we have at our disposal, that you can't give us an answer?"

Ethan glanced at Will apologetically, "Yes I'm afraid I am at the moment. But you can rest assured that we are doing everything we can..."

"Well that worked for that poor girl," Jay spat.

"Jay..." Will tried to placate his brother, who looked disappointed that his brother wasn't backing him up, "I need some air!" And then he was gone.

Will sighed deeply, "I'm sorry Ethan, he gets like that sometimes."  
"I don't blame him," Ethan said, "I feel exactly the same way."

"I know," Will breathed, "So what now?"

"Well as I told Jay, everyone is working flat out to find out what it is, but as I'm sure you know, if the paralysis carries on, your airway will become compromised which..."  
"Could lead to heart failure. God how could this happen?" Will asked rhetorically.

Ethan shrugged, "Who knows. Wrong place, wrong time - your immune system could have been compromised by something else - could be any number of things. But I promise you we will fight this with everything we have," the younger doctor vowed as he laid a hand on Will's arm.

"I know you will Ethan. I trust you."

"Try to rest," Ethan advised him.

"I will if you would do me a favour?"

"Name it?"

"Will you go and find Jay - just make sure he's alright...please," Will's voice faltered.

"Of course I will - please just rest," Ethan said as he left the room and closed the door. He took a moment to watch his friend as he pulled the cover over himself a little more, then he let out a breath and turned away.

"You're doing everything you can," Maggie caught his eye.

"I just hope it's enough," he told her with a heavy heart.

Jay made his way back into his brother's room about half a hour after he had stormed out. Ethan had found him and talked him through possible scenarios and had also mentioned that Will had asked him to find the detective because he was worried about how he was coping. Jay had apologised to Ethan for his initial outburst, but the young doctor wouldn't hear of it. He assured the young man that he completely understood his feeling of helplessness.

The young detective pulled up a chair beside his brother's bed and just watched the red haired doctor as he slept. He looked so peaceful. No sign of whatever it was that was ravaging his body. Jay couldn't help himself as he took hold of the nearest hand.

"God Will, you certainly know how to cause a scene don't you?" he forced out, tryng to push down the emotions that were threatening to overflow.

"Got to keep you on your toes," he heard the soft whisper coming from the bed.

Jay chuckled, "Answer for everything," he told his brother.

"Jay," Will wanted his attention.

Jay stood so that Will could see him better, still holding his hand, "You're holding my hand?"

Jay held it up into his vision, clearly confused as to why Will was mentioning it, "I can't feel it," Will breathed out.

The lead weight that had lodged itself in Jay's stomach earlier began to creep up his throat, "Wh...what?"

"I can't feel your hand holding mine. I think you'd better get Ethan," he all but whispered.

Terrified, Jay managed to gently place his brother's hand back on the bed and went in search of Ethan who he found in the break room talking to Natalie.

"Ethan, thank god - Will's getting worse. He couldn't feel me holding his hand...it's getting worse really quickly - I..."

Ethan jumped to his feet as tears finally gathered in Jay's eyes and his hands began to shake. Natalie noticed this and guided the younger Halstead brother to a seat and poured him a coffee which he took with gratitude but found difficult to keep a hold of because his hands were shaking so much.

Natalie looked distraught too, "It seems to be moving quicker than we anticipated," she remarked.

Jay just nodded, not trusting himself to speak. Natalie placed a hand on his arm, which was Jay's undoing. Tears tracked down his cheeks unchecked as he struggled with what was happening, "I can't lose him Nat. For all we argue and fight, he's my big brother - I can't imagine a world without him in it...I just can't..."

Natalie put her arm around him and pulled him into a gentle embrace, "I know. Owen adores him and so do I so we can't imagine it either..."

The door opened and Ethan walked partially in, "Guys he is getting worse and we still don't really know what we're dealing with but I suggest that you go in there because I think we're going to have to intubate and I think seeing familiar faces will help him."

They both jumped to their feet, their fear forgotten for the time being - their sole purpose now was to get to the stricken man. Jay slowed to a walk as he neared the room as he didn't want to show Will that he was so freaked out. He closed the door behind him, mindful that Will didn't want Natalie to be in there with him in case she could catch whatever it was.

He noticed that his brother's eyes were closed so he gently touched his arm, but there was no response. Jay glanced at Ethan, who had followed him in, "He can't feel you..." was all the doctor told him.

Jay's heart clenched as his shaking hand reached up to smooth down his brother's unruly red hair, this time Will opened his eyes, "Hey," he whispered.

"Hey yourself. Trust you to be in such a rush..." Jay choked out, trying to lighten the mood.

Will tried to smile, " Nat?"

"She's outside. I literally had to close the door in her face. Not sure I'm her most favourite person at the moment."

Will smiled as he tried to take in a deep breath but ended up coughing so Ethan sat him up a bit. The stricken doctor moved his head round, smiling when he saw Natalie through the window. She smiled back through tears as she blew him a kiss.

"Jay..." Will whispered quietly so his brother had to lean down to hear him, "If the worst happens, please look after Nat for me..." he coughed slightly once more, "And look after yourself. You are an amazing person, and for all our fights and arguments...just know that I love you brother..."

His eyes closed as alarms all around him began to scream.

"Will, Will, come on don't do this to me, to us. It's Christmas next week, Owen will want you there to help him open his presents!" Jay begged as Ethan moved him out of the way and began to intubate. Jay wouldn't be moved however, and kept a firm grip on his brother's hand. The door flew open allowing an emotional Natalie access to the room and she headed straight for the other side of the bed and held on to the man she loved. She glanced over the bed to see the same fear she felt coursing through her body in the eyes of the young man opposite her. She tried to offer an encouraging smile as they settled in to their vigil...

 **So I've left it there as I don't know whether I'm going to do any more and if I do, do I let him go or will there be a Christmas miracle (all be it a little late).**


	2. Chapter 2

**So here is a second (and final) chapter.**

 **Thank you to Andorian Ice Princess for your review. There might be a touch more Manstead just for you in this chapter - but is it the right brother?**

 **Chapter 2**

The snow was still falling, just as it had been for the last twelve hours. Jay was acutely aware of this because he had seen every hour of the last twenty four! He sat on the window seat nursing his hot coffee as he watched people trying to go about their lives on a Christmas Eve that was plagued by a good six feet of snow in some places. The blanket muffled the normal, every day sounds, apart from the screeching and laughing from the usual neighourhood snowball fight. Jay smiled wistfully, caught in a memory of the years when he had been a part of it.

Not this year though.

He had just come through one of the most traumatic weeks of his life. A shudder ran through him as he thought, not for the first time, that his life may never quite be the same again.

He recalled , once more, the endless nights holding vigil by his brother's hospital bed, sometimes joined by Natalie, but mostly alone. He had watched helplessly as the paralysis took hold of his brother, with seemingly no real hope of curing him. He had begged Will not to leave him...to hang on...to fight it. Then the morning had come when thye alarm on the life support machine had changed to a continuous tone...

He was brought out of his thoughts by a knock on the door. He quickly stood and opened the door to a toddler's face beaming up at him,"Hey Owen," he greeted the child with a smile of his own. Owen reached out his arms so Jay picked him up immediately. Owen threw his arms around the detective's neck and hugged him close. Jay could feel himself melting into the little boy's embrace. Presently, Natalie followed, brushing the snow from her coat as she juggled a couple of bags of presents, taking them straight to the tree, "Owen honey, why don't you put the presents under the tree for Uncle Jay?"

Jay placed the young boy on the floor, chuckling as he all but dived in the bags of presents.

"Coffee or hot chocolate?" He asked Natalie after he had taken her coat.

"Coffee would be great, thanks," she smiled.

"Did you have much trouble getting here in the snow?" Jay asked while he busied himself making the coffee.

"No not really. My car's really good in the snow and I took it easy anyway," she told him.

They both moved to the sofa and sat down carefully so as not to spill their hot drinks.

The sat in companionable silence for a while each watching the young child as he arranged the presents around the tree, "So how have you been?" Natalie finally broke the silence.

"I'm ok. What about you?"

"Owen keeps my mind off things...you look tired, have you been sleeping?" she asked, concerned about his exhausted features.

Jay suddenly found the floor very interesting, "I've been sleeping some...probably not as much as I should," he admitted as Natalie nodded her understanding, "I close my eyes and I'm taken back..." he choked, unable to continue.

Natalie placed a gentle hand on his arm, "It's ok...I do too..." her eyes filled with tears "But it will get less in time."

Jay blew out a deep breath, "Yeah...I guess..."

Their musings were cut short by a little body that launched itself between the two of them. Owen looked up at both of them, his cheery smile fading when he noticed their sad faces. Natalie noticed this and hugged her son close, "We're not really sad sweetheart - just sometimes we think of sad things. But you always make it better," she told him as she ruffled his hair, causing the little boy to giggle. Owen's laughter was infectious and pretty soon both adults were laughing too.

"What does a man have to do to get some peace and quiet round here?"  
Owen jumped down from the sofa and raced across the room, ready to throw himself at the figure. Jay followed close behind.

"Will!" The little boy cried at the top of his voice.

"Hey buddy," Will replied as he knelt down ready to receive the cannonball heading his way. Suddenly, Owen slowed down as if he had remembered that Will had been sick, and gently moved into the doctor's embrace, "So good to see you - I've missed you buddy," he told the boy as he tenderly stroked his hair.

Owen pulled back to look at him, "You ok now?"

The little boy's gaze was so intense that the older man began to feel uncomfortable, "I'm a lot better Owen," he told him honestly. Owen studied him a little while longer - satisfied that Will had told him the truth, he went back to his mother.

Jay, who had followed Owen to make sure that he didn't accidently hurt Will, chuckled at the exchange, "I could use him at the District," he said, "You need a hand getting up?" he asked as he saw his brother contemplating how he was going to get back to his feet. Will looked up at him gratefully as he took the offered hand. Jay kept an arm around his brother's waist as he supported him through the apartment. He had only been home from the hospital for a couple of days and although the paralysis was gone, it has left his body weakened so it didn't take much to exhaust him. Jay guided him to the sofa where he sat down next to Natalie and kissed her cheek, "Hey gorgeous - I've missed you."  
Jay made a gagging sound, "I can't sit here listening to that - coffee Will? A refil Nat?"

"Yes please, " they replied in unison, causing Jay to roll his eyes. He leaned down to Owen, "You was a cookie buddy?"

The little boy clapped, "Yey cookies!"

Jay offered him his hand and took him to the kitchen to give the couple a few minutes together.

As Owen sat on a stool, swinging his legs while munching on a cookie, Jay glanced to where his brother and his girlfriend were say. Will had his arm around Natalie, who in turn placed her head on his shoulder. They were talking quietly and every so often Will would plant a small kiss on the top of her head. Jay smiled, even though it reminded his of his time with Erin. He was pleased that his brother had finally got his act together, especially in light of recent events.

He turned round to find Owen with his hand in the cookie jar, "How may have you had young man?"

Owen pretended to count on his fingers then shrugged his shoulders.

Before long Natalie and Will came into the kitchen, the latter still unsteay on his feet, "What happened to the coffee bro?" Will looked round the kitchen.

"Oh god, I forgot! Been busy keeping an eye on the cookie monster here," he chuckled as Owen triumphantly held up another cookie before taking a bite.

Natalie went over to her son, putting the lid on the jar as she did, "I think you've had enough young man," she told him as she wiped the crumbs from his face, "It's time to go Will is tired," she told the small boy.

Jay helped them both with their coats, "You sure you'll be ok driving in this?" Will asked with concern, "You can stay here you know, it's not a problem."

Natalie stood on her tip toes and kissed him on the lips, "I'll be fine. We're seeing each other anyway tomorrow."

Will still didn't look happy about it but he accepted it as Jay walked them to the door, "Text him when you get home otherwise he'll be up all night worrying."

"Of course I will, " she agreed and kissed his cheek. Owen shouted his goodbyes and then they were gone.

Jay locked the door behind them and turned round just in time to see the last of his brother's energy disappear. He caught him gently, "Bed or couch?"

"I want to say couch so badly but I think bed would be a better idea," he told him.

Jay walked him into his room and helped him into bed, "Thanks Jay, for everything. I wouldn't have made it this far without you," he told him truthfully.

Jay ducked his head, "You'd have done the same for me...I hope," he finished with a sideways glance at his brother.

Will laughed, "Well...I'd have to think about it..." His expression darkened when he noticed that his younger brother was not sharing the joke, "Jay?"

His brother looked at him, his eyes full, much to the older man's surprise, "I was so scared Will..."

"I know, me to."

"No I mean really scared. I hadn't felt that way since combat...you were literally dying before my eyes - hell you did actually die for a few minutes and there was nothing I could do to help you - nothing!"

The threatening tears cascaded down his cheeks now, but he didn't bother to wipe them away.

Will beckoned him and brought him into a warm embrace, "You kept me alive Jay. You made me fight. Don't think that I didn't know you were by my side every step of the way. I could hear you begging me not to leave you. You gave me something to fight for. I know I'm lucky enough to have Nat and Owen in my life now, but you're my brother, my flesh and blood - you made me get well again."

By now both brothers could not control the emotions that were pouring out of them.

Finally, Jay pulled away but kept a hold of one of Will's hands, "Well I guess my hard man reputation is definitely shot now," he chuckled throught the tears.

"What reputation?" Will countered.

"Oh ha ha - see you so called sense of humour didn't leave you."

"Never," Will replied, stifling a yawn.

Suddenly his phone lit up and the older man grabbed it smiling as he read the message.

"Nat got home ok?" The younger man questioned.

Will nodded as he set his phone back down on the table.

"Do you need anything before I go to bed?" Jay asked, stifling a yawn of his own.

Will shook his head, "Just for you to get a good night's sleep. I know you haven't been sleeping that well."

Jay smiled ruefully, "You don't miss a thing do you?"  
"Nope," the older man chuckled.

As Jay closed the door to the bedroom, he stopped and turned to his brother, "It's good to have you home."

"It's good to be back home little brother."

 **There you have it. Complete fluff. Happy new year to you all xx**


End file.
